Sometimes models are surprisingly smart.

All the normal matter in the Milky Way disc is denser than the dark matter that surrounds it.

Speculation and the exploration of ideas beyond what we know with certainty are what lead to progress.

If such external influences are intrinsic to religion, then logic and scientific thought dictate that there must be a mechanism by which this influence is transmitted. A religious or spiritual belief that involves an invisible undetectable force that nonetheless influences human actions and behavior or that of the world itself produces a situation in which a believer has no choice but to have faith and abandon logic--or simply not care.

Although I was first drawn to math and science by the certainty they promised, today I find the unanswered questions and the unexpected connections at least as attractive.

I'm not creating the universe. I'm creating a model of the universe, which may or may not be true.

Physics has entered a remarkable era. Ideas that were once the realm of science fiction are now entering our theoretical — and maybe even experimental — grasp. Brand-new theoretical discoveries about extra dimensions have irreversibly changed how particle physicists, astrophysicists, and cosmologists now think about the world. The sheer number and pace of discoveries tells us that we've most likely only scratched the surface of the wondrous possibilities that lie in store. Ideas have taken on a life of their own.